Lining my duckies up for a possible set of IJA tanks. Got the Hataka set and they have early and late colors. Up until 42 it was THE IJA scheme with the yellow squiggles. (I've seen not seen anything in print but I get feel the yellow was only for mainland Asia, Indonisia, Philippines ..... stuff out in the Marianas and such did not have yellow. ) Finally ... to my question .... Colors changed in 43. Would anything assigned to island defenses in the Pacific ... Guam, Saipan, have been repainted? I'm thinking, no, they had more important stuff to transport than paint. A second opinion please?

Japanese armor pretty much remained in the scheme the manufacturer painted it in. The yellow lines on earlier schemes were applied to break up the vehicle profile. I'm not aware of vehicles painted for specific locations, so vehicles sent to Pacific islands would also feature the yellow bands, based on when they were manufactured.

The official color scheme changed in 1942, but manufacturers probably used up their remaining stocks of paint before switching over to the new scheme. Vehicles in the field were not repainted - except for touch up on severely worn or damaged spots. As you stated, there were much more important things to transport than paint.

Tim , I've also entered the world of Japanese armor . The yellow " squiggle was dropped after a certain time frame , 42-ish and were predominately used on mainland Southeast Asia and the Philippines .
Prior to 42-ish , Japanese tanks were painted a base color of light military brown [ whatever that was ] in the factory and units they were assigned to did their own hand painted camo schemes .
After 42 the factories base painted the tanks in a khaki drab color , to be camo hand painted in the units assigned .
The other two colors applied were a brown , some claim a redish brown , but mostly a brown earth color and a green akin to olive drab .
Sprayed colors were rare and examples were seen late in the war .
The differences in mainland Asia tanks and island tanks were due to the fact that island tanks were under the IJN control .

Here's a good ref that I've been using
http://www3.plala.or.jp/takihome/

Here is another article from Taki in a discussion on Missing Lynx. https://www.tapatalk.com/groups/missinglynx/yushukan-chi-ha-colours-t319893.html

There is still some discussion on the exact colors and I have read that depending on location a tank might be repainted somewhat to match local terrain. If you can find a closeup of a Japanese tank you can often see the brush marks. It is very clear on the burned tanks at Guadalcanal.

Some good info here: https://ipmstoronto.files.wordpress.com/2014/12/japanese-armour-colours-1937-1945_harvey-low1.pdf